assertArgumentNotNull("channel", channel);

        try {
            return channel.size();
        } catch (final IOException e) {
            throw new IORuntimeException(e);
        }
    }

    /**
     * Reads the contents of the file channel into a byte buffer.
     *
     * @param channel
     *            The file channel. Must not be {@literal null}.
     * @param buffer

    try {
      RandomAccessFile raf =
          closer.register(new RandomAccessFile(file, mode == MapMode.READ_ONLY ? "r" : "rw"));
      FileChannel channel = closer.register(raf.getChannel());
      return channel.map(mode, 0, size == -1 ? channel.size() : size);
    } catch (Throwable e) {
      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }

  /**

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3

import java.net.InetAddress
import java.net.Socket
import java.nio.channels.SocketChannel
import javax.net.SocketFactory

class ChannelSocketFactory : SocketFactory() {
  override fun createSocket(): Socket = SocketChannel.open().socket()

  override fun createSocket(
    host: String,

    try {
      RandomAccessFile raf =
          closer.register(new RandomAccessFile(file, mode == MapMode.READ_ONLY ? "r" : "rw"));
      FileChannel channel = closer.register(raf.getChannel());
      return channel.map(mode, 0, size == -1 ? channel.size() : size);
    } catch (Throwable e) {
      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }

  /**

   * <ol>
   *   <li>Use sendfile(2) or equivalent. Requires that both the input channel and the output
   *       channel have their own file descriptors. Generally this only happens when both channels
   *       are files or sockets. This performs zero copies - the bytes never enter userspace.
   *   <li>Use mmap(2) or equivalent. Requires that either the input channel or the output channel

 */
package okhttp3

import java.io.IOException
import java.io.InputStream
import java.io.OutputStream
import java.net.InetAddress
import java.net.SocketAddress
import java.net.SocketException
import java.nio.channels.SocketChannel
import java.util.function.BiFunction
import javax.net.ssl.HandshakeCompletedListener
import javax.net.ssl.SSLParameters
import javax.net.ssl.SSLSession
import javax.net.ssl.SSLSocket

        final FileInputStream is = InputStreamUtil.create(file);
        try {
            final FileChannel channel = is.getChannel();
            final ByteBuffer buffer = ByteBuffer.allocate((int) ChannelUtil.size(channel));
            ChannelUtil.read(channel, buffer);
            return buffer.array();
        } finally {
            CloseableUtil.close(is);
        }
    }

    /**

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel.MapMode;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel.MapMode;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**

        assertArgumentNotNull("out", out);

        final FileOutputStream os = OutputStreamUtil.create(out);
        try {
            final FileChannel channel = os.getChannel();
            final ByteBuffer buffer = ByteBuffer.wrap(in);
            return ChannelUtil.write(channel, buffer);
        } finally {
            CloseableUtil.close(os);
        }
    }

    /**